It's relevant because it's the reason she's getting $1k in payments in the first place, as a settlement from whoever was responsible for the lead. It's not that she sold welfare payments and wants to explain away the bad decision with lead. It's that she's a damaged person (lead is a neurotoxin), got settlement payments, and made a bad decision that's more understandable in that context. Without the lead dialogue, she made a bad decision she could've prevented herself you might be able to argue. With the lead dialogue it's, on a mental level, probably quite similar like stealing candy from a baby. Now imagine the baby has to live off of settlements for decades, which have just been reduced by a gigantic amount. Now consider what it means in 5 years when the money's gone (even if she spent as frugally as normal, living on $12k per year tops), and you know she's going to either become homeless or severely dependent on the state or likely a combination of both. That's horrible for her first and foremost, and it doesn't help us or our society, either. Lead played a big role in this. Hell even outside of the 'bad decision', a normal person who lost out on $1m in benefits could still go to work, live a normal life. She can't because she's damaged by lead. (it doesn't talk about it deeply but it says for example she can't live alone or work).